Vacuum cleaner assembly



June 28, 1966 GRELLSSQN 3,257,784

VACUUM CLEANER ASSEMBLY Filed April 1, 1963 5 Sheets-Sheet 1 FIG. 10/

/%VL MINVENT ATTORNEY June 28, 1966 R Lsso 3,257,784

VACUUM CLEANER ASSEMBLY Filed April 1, 1965 5 Sheets-Sheet 5 FIG. 4

I NVENTOR.

42;: W W @J/M 44 ATTORNEY United States Patent 3,257,784 VACUUM CLEANER ASSEMBLY Karl Gustav Grelisson, Solieutuna, Sweden, assignor to Alrtiebolaget Eiectrolux, Stockholm, Sweden, a corporation of Sweden Filed Apr. 1, 1963, Ser. No. 269,443 Claims priority, application Sweden, Apr. 3, 1962, 3,717/62 1% Claims. (Cl. 55-472) My invention relates to suction cleaners.

An object of my invention is to provide an improved suction cleaner of simplified construction which can be readily assembled.

Another object of my invention is to provide an improved suction cleaner having a compact arrangement of parts and in which operating elements are readily accessible for repair or replacement. I accomplish this by providing a suction cleaner having separable first and second cleaner components for respectively housing a dust collector and a motor-fan unit, and maintaining the dust collector anchored between the cleaner components by connecting means employed to detachably connect the cleaner components together. More particularly, an apertured partition disposed between the motor-fan unit and the dust collector frame and forming a part of the second cleaner component housing the motor-fan unit is provided with flanges projecting from opposing sides thereof, one of the flanges forming a part of structure for supporting the motor-fan unit in the second cleaner component and the other flange serving to maintain the dust collector in its anchored position between the partition and the first cleaner component when the cleaner components are detachably connected together.

Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a side elevational view, partly broken away and in section, of a suction cleaner embodying my invention;

FIG. 2 is a fragmentary perspective view of the rear end of the suction cleaner shown in FIG. 1;

FIG. 3 is an enlarged longitudinal sectional view, taken vertically midway between its side walls, of the rear end of the suction cleaner shown in FIG. 1;

FIG. 3a is a fragmentary longitudinal sectional View 1 which complements FIG. 2 and illustrates corner details of the suction cleaner shown in FIG. 1;

FIG. 3b is a sectional view taken at line 3b-3b of FIGS. 1 and 3a to illustrate corner details of the suction cleaner more clearly;

FIG. 4 is an enlarged fragmentary sectional view of parts shown in FIG. 1; and

FIG. 5 is a perspective view of parts shown in FIGS. 1 and 4, said figure omitting element Ma.

Referring to FIG. 1, I have shown my invention embodied in a portable elongated tank-type cleaner having a casing 11 which is provided with a handle 12 andrunners 14- and 15 that extend lengthwise of the casing and are fixed thereto in any suitable manner to facilitate movement thereof on a supporting surface.

The casing 11 is formed of two parts comprising opencnded front and rear casing sections 11a and 11%, respectively, which include integrally formed closed ends 101a and 11b and are detachably connected together at their open ends by clamps 16 at opposing sides of the casing, the runners 14 and 15 being respectively fixed to the front and rear casing sections Julia and 11b. The bottom 11a" ice of the front casing section 11a, which is cup-shaped and defines a space 17 to receive a dust collector 18, communicates with a hollow fitting 19, the outer end 19a of which constitutes the air inlet of the cleaner and to which a flexible suction hose or suction cleaner wand may be detachably connected.

A motor-fan unit 20 is located in the space 21 defined by the rear casing section 11b which also is cup-shaped and includes a centirfugal fan 22 carried at one end of an electric motor 23. The motor-fan unit 20 is controlled by a switch (not shown) which is arranged to be actuated by an operating member 24 located in a recessed part 25 at the closed end of the rear casing section 11b, as shown in FIG. 2.

When the suction cleaner is being operated and the fan 22 driven by the motor 23, dust-laden air flowing through a wand or suction hose connected to the air inlet 19a is drawn through the latter into dust collector 18 in the front casing section 11a. During the cleaning operation, dust collects in the dust collector 18, and air from which dust has been removed passes through the dust collector into an inlet 26 of the fan 22. The air is discharged from the fan 22 and flows through the motor 23, and thereafter is discharged through a hollow fitting 27 which communicates with the space 21 at the bottom 11b" of the rear open-ended cup-shaped casing section 11b and constitutes the air outlet 27a of the cleaner.

A partition 28 is disposed between the front and rear casing sections 11a and 11b and formed with a plurality of openings 29 through which air passes from the space 17 to the inlet 26 of the fan 22, as best shown in FIGS. 3 and 4. As will be described hereinafter, the partition 28 is removably secured to the rear casing section 11b and forms a unitary part thereof. Since partition 28 normally is fixed to the rear casing section 1111 and is removed therefrom only when it is necessary to inspect or repair the -motor-fan unit 22, the rear casing section 111) and partition 28 collectively may be referred to as a rear component 10b of the cleaner 10, and the front casing section 11a may be referred to as a front component 10a of the cleaner.

In accordance with my invention, the partition 28 is provided with forwardly and rearwardly extending inner and outer flanges 28a and 2812, respectively, the flanges 28a and 23b being of annular form with the peripheral edge portion 280 of the partition projecting radially outward from the outer flange 2812, as shown in FIGS. 3 and 4. The peripheral edge portion'28c of the partition 28 snugly receives an annular-shaped sealing member 30 which is formed of resilient material, such as rubber, for example, and is generally U-shaped in section. The rear casing section 11b is notched at 11b to receive the base or closed end of the U-shaped sealing member 30, and the spaced arms of the sealing member extend toward and bear against the flanges 28a and 2811, respectively. One arm of the U-shaped sealing member 30 projects radially outward and forms a rib 30a which bears against the extreme end edge of the rear casing section l lb.

When the partition 28 is removably secured to the rear casing section 11b, it will be evident that the sealing member 30 is firmly anchored against the extreme end edge of the rear casing section 11b and forms the exposed end of rear component 1% of the suction cleaner. When the front and rear cleaner components 104: and 1012 are detachably connected together by the clamps 16, the rib 36a of the sealing member forms a joint between the components, as seen in FIG. 4. The partition 28 at the corners thereof is formed with openings 31, one of which is shown in FIG. 3a, which receive threaded bolts 32 having tightening nuts 33 held in fixed positions in any suitable manner between spaced ribs 34 which are provided at the inner surface of the rear casing section 11b and extend lengthwise thereof, as best shown in FIGS. 3a and 3b.

In accord with my invention, the partition 28 is effectively employed to resiliently anchor the motor-fan unit in position in the rear casing section 11b. As shown in FIG. 3, an apertured annular body of resilient material, such as natural or synthetic rubber, for example, is disposed between the rear end of the motor 23 and a wall member 36 at the bottom 11b" of the rear casing section 11b. The resilient body 35 conforms to the irregularly-shaped configuration of the motor 23 and wall member 36 against which it bears to obtain a snug fit therebetween, the coacting parts being of such shape that relative angular movement about the axis of the motor 23 is prevented between the motor and the resilient body 35 and between the latter and the end wall member 36.

The front end of the fan 22, at the vicinity of the partition 28, receives a member 37 of annular form which .is L-shaped in section and may be formed of resilient material, such as rubber, for example. The arms 37a and 37b of member 37, which are at a right angle with respect to one another, form an open-bottomed cup in which the front end of the fan 22 nests. The arm 37a at its inner surface is formed with a boss 370 of annular form which bears against the front end of the fan 22 to absorb axially extending components of vibrations developed by the motor-fan unit 20; and the arm 37b, which bears snugly against the side of the fan 22, is formed with a boss 37d of. annular form at its outer surface which bears against the flange 28b to absorb radially extending components of vibrations developed by the motor-fan unit 20.

It will now be understood that the motor-fan unit 20 is anchored in position in the rear cup-shaped casing section 11b by the removably secured partition 28 which essentially clamps the motor-fan unit endwise between the resilient members 35 and 37. As just explained, the arms 37a and 37b of the resilient member 37 function to absorb axially and radially extending components of vibrations developed by the motor-fan unit. The resilient member 35 nests in a cup-shaped part of the wall member 36, whereby the resilient member 35 also functions to absorb axially and radially extending components of vibrations developed by the motor-fan unit 20.

The partition 28 is also effectively employed to anchor the dust collector 18 in position in the cup-shaped front casing section 11a when the front and rear open-ended casing sections 11a and 11b are connected together by the clamps 16. The dust collector 18 comprises a selfsustaining frame structure 38 which is formed of lightweight metal or stiff plastic elements and includes spaced fingers or ribs 39 extending axially of the frame structure between an open end ring member 40* at an opening 41 which defines the open end of the dust collector 18 and an apertured bottom end ring42, and a plurality of axially spaced rings 43 disposed between the bottom end ring 42 and the end ring 40 at the open end of the dust collector 18 to reinforce the frame structure 38. The axially extending ribs 39 at 39a overlap the bottom end ring 42 at the closed end of the dust collector 18, the extreme end portions 39a of the ribs overlying the peripheral outer surface of the apertured bottom end ring 42. Within the frame structure 38 and integrally united to the inner surfaces of the axially spaced rings 40, 42 and 43 are one or more layers of material which are pervious to air and function as a filter 44 to remove dust and dirt from air. When the dust collector 18 is positioned in the open-ended cup-shaped front casing section 11a, the open end ring 40 at the open end 41 of the dust collector 18 bears against an annular-shaped sealing member 45 which is formed of resilient material like rubber, for example, and snugly fits in a recess 46 at the inner surface of the bottom 11a" of the cup-shaped front casing section, as best shown in FIG. 4.

If desired, a removable paper dust bag 48 may be employed within the dust collector 18. As shown in FIG. 4, the mouth of the bag 48 extends through the open'end 41 of the dust collector with the lip 48a of the mouth folded over the end ring 40. With this arrangement, the lip 48a is disposed between the front casing section 11a and the end ring 40 and the sealing member 45 bears against the folded-over lip of the paper bag to hold the paper bag in sealing relation therewith.

When the front and rear cleaner components 10a and 10b are connected together by the clamps 16 with the open end 41 of the dust collector 18 in sealing relation with the front sealing member 45, the dust collector, due to the axially extending ribs 39, is yieldingly clamped between the front sealing member 45 and the partition 28. In its clamped position, the extreme ends 39a of the axially extending ribs 39 of the dust collector 18 are seated within .the forwardly extending flange 28a and the end portions 39a of the axially extending ribs 39 and the open end ring 42 at the closed end of the dust collector 18 space the filter 44, including the transverse part 44a thereof at the bottom end ring 42, radially from the flange 28a; and a boss or ridge 28d of annular form and of smaller diameter than the ring 42, which extends forward from the partition 28, as shown in FIGS. 1 and 3A, is adapted to act against the bottom portion 44a of the filter 44 to space the filter 44 axially from the partition 28, the open bottom ring 42 and the part 44a of the filter 44 defining the closed end of the dust collector 18, as shown in FIG. 4, whereby flow of air through the filter 44 will not be obstructed and air flow therethrough will be promoted.

As shown in FIGS. 1, 3, 3A and 4, a plurality of ribs 49 and 49a are distributed about the flange 28a and extend radially outward therefrom, the ribs 49a being radially wider than the ribs 49 in view of the crosssectional shape of the cleaner, as best shown in FIG. 2. However, all of the ribs are of such axial length that they function as positioning guides for the open end of the front casing section 11a when it is positioned over the flange 28a against the sealing member 30, as shown in FIG. 4. With the open end of the front casing section 11a positioned over the outer extremities of the ribs 49 and 49a in abutting relation with the sealing member 30, the clamps 16 can be employed to draw the front casing section 11a toward the rear casing section 11b and connect the front and rear cleaner components 10a and 10b together.

If desired, the rear cleaner component 10b may be employed as a blower unit to provide a source of heated air for operating a hair dryer. Accordingly, the cleaner components 10a and 10b may be detached from one another and the rear cleaner component 10b may be supported in an erect position on the flange 28a, the latter serving as a supporting base and being formed with notches 28a to permit clean ambient air to pass therethrough and flow into the inlet 26 of the fan 22 when the motor-fan unit 20 is being operated. The air flowing from the fan 22 passes through the motor 23 and becomes heated, such heated air being discharged from the outlet 27a to which may be connected an air inlet connection of a hair dryer.

It will now be understood that the casing 11 comprises an open-ended cup-shaped front casing section 1111 having a bottom 11a and an open-ended cup-shaped rear casing section 11b having a bottom 11b". The front and rear cup-shaped casing sections 11a and 11b respectively have first and second openings 19a and 27a at the bottoms thereof, the first and second openings 19a and 27a respectively defining the inlet an outlet for air. As best shown in FIG. 4, an extreme end portion or flange 11a of the front casing section 11a projects beyond the bottom 11a" thereof which is formed with an opening (not shown) with which the hollow fitting 19- communicates.

The means for moving air comprises a motor 23 and fan 22 driven thereby, the motor 23 and fan 22 defining a motor-fan unit 20. The partition 28 and fastening elements 32 and 33 therefor comprise means for mountthe motor-fan unit 20 in the rear casing section 11b with the fan 22 adjacent to the open end thereof and the motor 23 adjacent to the second opening 27a defining the air outlet.

The dust collector 18 comprises an elongated member 38 having first and second ring-shaped ends 40 and 42, respectively, and an elongated cup-shaped dust holder including a filter 44 comprising suitable filter material. In the preferred embodiment illustrated, the elongated member 38 comprises an apertured frame having transverse ring-shaped elements 40 and 42 at the ends thereof and spaced transverse rings 43 therebetween, all of which are axially spaced from one another. The transverse rings are connected by axially extending ribs 39. The frame parts 39, 4t), 42 and 43 may be formed of stiff plastic elements which are connected to one another and have inner surfaces.

The material forming the filter 44 defines an elongated cup-shaped dust holder having a bottom 44a at the second ring-shaped end 42 of the elongated member or frame structure 38 and an access opening 41 for air at the first ring-shaped end 49 thereof for flowing air from the inlet 19a into the interior of the dust holder 44 and flowing air from which dust has been removed from the exterior of the dust holder 44 to the outlet 27a. The axially extending filter 44 engages the inner surfaces of the apertured frame parts 41 42 and 43, as best shown in FIG. 4, and is disposed in the path of flow of air. It will be seen in FIG. 4 that the inner surfaces of the rings 40, 42 and 43 are spaced radially from the axially extending ribs 39 to provide gaps 47 therebetween.

The front cup-shaped casing section 110 is provided with a first part in the form of a resilient member 45 which is seated in a ring-shaped groove at the vicinity of the bottom 11a" of the front casing section 11a, the part 45 being axially removed from the open end of the front casing section. The rear cup-shaped casing section 11b is provided with a second part 23a of annular form which is carried by the partition 28 at the open end of the rear casing section. The parts 45 and 28a in the front and rear casing sections 110 and 11b, respectively, anchor the dust collector 18 between the casing sections when they are detachably connected by the clamps 16. When this is done, the first end or ring 4t) of the dust collector 1S exerts force against the first part 45 and the second end or ring 42 thereof exerts force against the second part 28a. Since the ribs 39 are stiff and may be formed of plastic, as explained above, these parts of the dust collector 155 are stiffer than the material employed to provide the filter 4d. The first and second end rings 4ft and 42 respectively engage the air access end 41 and bottom 44a of the cup-shaped dust holder 44. The frame or elongated member 38 is capable of yielding and being axially compressed when the dust collector 18 is anchored between the front and rear casing sections 11a and 11b, respectively, with the first ring-shaped end 44 exerting force against the first part 45 and the second ring-shaped end 42 exerting force against the second part 28a when the casing sections are detachably connected by the clamps 16.

Although I have shown and described a single embodiment of my invention, 1 do not wish to be limited to the particular arrangement set forth, and I intend in the following claims to cover all modifications which do not ended cup-shaped front casing section having a bottom, an open-ended cup-shaped rear casing section having a bottom, said front and rear casing sections respectively having first and second openings, said first and second openings respectively defining the inlet and outlet for air, the means for moving air comprising a motor and a fan driven thereby, said motor and fan defining a motorfan unit, means for mounting said motor-fan unit in said rear casing section with said fan adjacent to the open end thereof and said motor adjacent to the second opening defining the air outlet, said dust collector being disposed in said front casing section, said dust collector comprising an elongated apertured frame of annular form having opposing first and second ends, said frame comprising a plurality of spaced elements connected .to one another and having inner surfaces, an elongated body of annular form at the inner surfaces of said elements which comprises filter material and extends between the first end and the opposing second end of said apertured frame and defines a cup-shaped dust holder having a bottom at the second end of said frame and an access opening for air at the first end thereof for flowing air from the inlet into the interior of said dust holder and flowing air from which dust has been removed from the exterior thereof to the outlet, said front cup-shaped casing section having a first part therein at the vicinity of its bottom, said rear cup-shaped casing section having a second part at the open end thereof, said dust collector being adapted to extend axially within said casing with the first end thereof adjacent to said first part and the second end thereof adjacent to said second part, and means for detachably connecting the open ends of said front and rear casing sections and anchoring said apertured frame between said casing sections with its first end exerting force against said first part and its opposite second end exerting force against said second part.

2. A suction cleaner as set forth in claim 1 which includes an apertured partition, means for detachably fixing said partition to said rear casing section at the open end thereof, said apertured partition being disposed between said motor-fan unit and said apertured frame, said second part being carried by said apertured partition, said apertured partition being formed with openings, said means for detachably fixing said apertured partition to said rear casing section including threaded bolts extending through the openings in said'partition, and apertured threaded members fixed to the inner surface of said rear casing section which receive said threaded bolts for fixing said partition to said rear casing section.

3. A suction cleaner as set forth in claim 2 in which said rear casing section at its inner surface is provided with pairs of spaced axially extending ribs, each of said pairs of ribs having a threaded n-ut fixed thereto which bridges the gap between said ribs and serves as said threaded apertured member.

4. A suction cleaner as set forth in claim 1 which includes an apertured partition, means for detachably fixing said partition to said rear casing section at the open end thereof, said partition having first and second flange means at opposing sides thereof, said first flange means projecting axially of said rear casing section in one direction from the open end thereof toward the second opening defining the outlet and said second flange means projecting axially of said rear casing section in the opposite direction from said one direction at the open end of said rear casing section, said means for mounting said motor-fan unit in said rear casing section including said partition and said first flange means, and said second flange means serving as said second part to anchor said apertured frame between said casing sections.

5. A suction cleaner as set forth in claim 4 in which said second flange means is of annular form and serves as a base for supporting said rear casing section in an erect position when detached from said front casing section, and said second flange means being apertured to enable air to flow therethrongh during operation of said motorfan unit when said rear casing section is detached from said front casing section and supported in the the erect position.

6. A suction cleaner as set forth in claim 4 in which said second flange means includes means for spacing the second end of said elongated apertured frame from said apertured partition when said frame is anchored between said first and second parts of said front and rear casing sections, respectively, by said detachable connecting means.

7. A suction cleaner as set forth in claim 4 in which said second flange means is of annular form and defines a seat to receive the second end of said elongated apertured frame, said seat functioning as the second part at the open end of said rear cup-shaped casing section, said elongated apertured frame having radially extending parts at the second end thereof which exert force against said second flange means to maintain said cup-shaped dust holder in spaced relation with said second flange means when said frame is anchored between said first and second parts of said front and rear casing sections, respec tively, by said detachable connecting means.

8. A suction cleaner as set forth in claim 4 which includes a sealing member fixed to the periphery of said apertured partition and having first and second axially extending portions at opposing sides thereof, the first portion of said sealing member being clamped between said partition and the open end of said rear casing section when said partition is fixed thereto by said detachable fixing means, the second portion of said sealing member being disposed between said partition and the open end of said front casing section when said front and rear casing sec tions are connected at their open ends by said detachable connecting means, and said second flange means being of annular form and having means for guiding said front casing section when said front and rear casing sections are moved toward one another to be connected at their open ends by said detachable connecting means.

9. In a suction cleaner of the class described having a casing formed with an inlet and outlet and a path of flow for air therebetween and means for moving air in the path of flow and a dust collector in the path of flow for removing dust from air, the combination of an open-ended cup-shaped front casing section having a bottom, an openended cup-shaped rear casing section having a bottom, said front and rear casing sections respectively having first and second openings, said first and second openings respectively defining the inlet and outlet for air, the means for moving air comprising a motor and a fan driven thereby, said motor and fan defining a motor-fan unit, means for mounting said motor-fan unit in said rear casing section with said fan adjacent to the open end thereof and said motor adjacent to the second opening defining the air outlet, said dust collector being disposed in said front casing section, said dust collector comprising an elongated member having opposing first and second ringshaped ends and an elongated cup-shaped dust holder comprising filter material, said dust holder having a bottom at said second ring-shaped end of said elongated member and an access opening for air at the first ring-shaped end thereof for flowing air from the inlet into the interior of said dust holder and flowing air from which dust has been removed from the exterior of said dust holder to the outlet, said elongated member of said dust collector being stiffer than said filter material and extending axially of and alongside said elongated cup-shaped dust holder with the opposing first and second ring-shaped ends respectively engaging the air access end and bottom of said cupshaped dust holder, said front cup-shaped casing section having a first part axially removed from the open end thereof, said read cup-shaped casing section having a second part at the open end thereof, and means for detachably connecting the open ends of said front and rear casing sections and anchoring said elongated member of said dust collector between said casing sections with said first ring-shaped end of said elongated member exerting force against said first part and the second opposing ring-shaped end thereof exerting force against said second part.

10. A suction cleaner as set forth in claim 9 in which said elongated axially extending member of said dust collector comprises material capable of yielding and being axially compressed between the opposing first and second ring-shaped ends thereof when said dust collector is anchored between said front and rear casing sections by said detachable connecting means with the first ringshaped end of said elongated member exerting force against said first part and the second opposing ring-shaped end thereof exerting force against said second part.

References Cited by the Examiner UNITED STATES PATENTS 2,464,401 3/1949 Kelly --467 2,643,733 6/1953 Shellman 55-467 2,988,170 6/1961 Pritchard 55-480 3,050,921 8/1962 Seyfried 55-467 3,142,857 8/1964 Fresard et al. 15327 FOREIGN PATENTS 527,655 6/ 1955 Italy. 286,085 2/ 1953 Switzerland.

HARRY B. THORNTON, Primary Examiner.

REUBEN FRIEDMAN, Examiner.

B. NOZICK, Assistant Examiner. 

1. IN A SUCTION CLEANER OF THE CLASS DESCRIBED HAVING A CASING FORMED WITH AN INLET AND OUTLET AND A PATH OF FLOW FOR AIR THEREBETWEEN AND MEANS FOR MOVING AIR IN THE PATH OF FLOW AND A DUCT COLLECTOR IN THE PATH OF FLOW FOR REMOVING DUST FROM AIR, THE COMBINATION OF AN OPENENDED CUP-SHAPED FRONT CASING SECTION HAVING A BOTTOM, AN OPEN-ENDED CUP-SHAPED REAR CASING SECTION HAVING A BOTTOM, SAID FRONG AND REAR CASING SECTIONS RESPECTIVELY HAVING FIRST AND SECOND OPENINGS, SAID FIRST AND SECOND OPENINGS RESPECTIVELY DEFINING THE INLET AND OUTLET FOR AIR, THE MEANS FOR MOVING AIR COMPRISING A MOTOR AND A FAN DRIVEN THEREBY, SAID MOTOR AND FAN DEFINING A MOTORFAN UNIT, MEANS FOR MOUNTING SAID MOTOR-FAN UNIT IN SAID REAR CASING SECTION WITH SAID FAN ADJACENT TO THE OPEN END THEREOF AND SAID MOTOR ADJACENT TO THE SECOND OPENING DEFINING THE AIR OUTLET, SAID DUCT COLLECTOR BEING DISPOSED IN SAID FRONT CASING SECTION, SAID DUST COLLECTOR COMPRISING AN ELONGATED APERTURED FRAME OF ANNULAR FORM HAVING OPPOSING FIRST AND SECOND ENDS, SAID FRAME COMPRISING A PLURALITY OF SPACED ELEMENTS CONNECTED TO ONE ANOTHER AND HAVING INNER SURFACES, AN ELONGATED BODY OF ANNULAR FORM AT THE INNER SURFACES OF SAID ELEMENTS WHICH COMPRISES FILTER MATERIAL AND EXTENDS BETWEEN THE FIRST END AND THE OPPOSING SECOND END OF SAID APERTURED FRAME AND DEFINES A CUP-SHAPED DUST HOLDER HAVING A BOTTOM AT THE SECOND END OF SAID FRAME AND AN ACCESS OPENING FOR AIR AT THE FIRST END THEREOF FOR FLOWING AIR FROM THE INLET INTO THE INTERIOR OF SAID DUST HOLDER AND FLOWING AIR FROM WHICH DUST HAS BEEN REMOVED FROM THE EXTERIOR THEREOF TO THE OUTLET, SAID FRONT CUP-SHAPED CASING SECTION HAVING A FIRST PART THEREIN AT THE VICINITY OF ITS BOTTOM, SAID REAR CUP-SHAPED CASING SECTION HAVING A SECOND PART AT THE OPEN END THEREOF, SAID DUST COLLECTOR BEING ADAPTED TO EXTEND AXIALLY WITHIN SAID CASING WITH THE FIRST END THEREOF ADJACENT TO SAID FIRST PART AND THE SECOND END THEREOF ADJACENT TO SAID SECOND PART, AND MEANS FOR DETACHABLY CONNECTING THE OPEN ENDS OF SAID FRONT AND REAR CASING SECTIONS AND ANCHORING SAID APERTURES FRAME BETWEEN SAID CASING SECTIONS WITH ITS FIRST END EXERTING FORCE AGAINST SAID FIRST PART AND ITS OPPOSITE SECOND END EXERTING FORCE AGAINST SAID SECOND PART. 